C / C++ / MFC

6-Aug-03 2:53

Hi,

I've got a CEdit control, and a CString --> the CString will contain CEdit's text after de DDX_TEXT call, but after this I need the CEdit to be empty. I've tried by emptying the string, and then calling UpdateData(), but that just fills the string with the content of the CEdit, instead of the other way around.

How can I do this?

Chris Meech6-Aug-03 3:10

Chris Meech

6-Aug-03 3:10

Try calling UpdateData(FALSE). The parameter is used to control the direction of data transfer.
TRUE -> data from window to CString
FALSE -> data from CString to window.

Chris Meech

"what makes CP different is the people and sense of community, things people will only discover if they join up and join in." Christian Graus Nov 14, 2002.

Oh and for those that ask programming questions in the lounge. Seek the truth here[^].

BoudewijnEctor6-Aug-03 3:23

6-Aug-03 3:23

Thank you, it really helped

David Crow6-Aug-03 3:10

David Crow

6-Aug-03 3:10

Since UpdateData() is an all-or-nothing operation, it shouldn't be used on individual updates.

m_edit.SetWindowText("");

CheckListBox event for checkbox

Vitali Halershtein6-Aug-03 3:20

Vitali Halershtein

6-Aug-03 3:20

Hi again student Poke tongue | ;-P

MSDN

BOOL UpdateData( BOOL bSaveAndValidate = TRUE );
Return Value
Nonzero if the operation is successful; otherwise 0. If bSaveAndValidate is TRUE, then a return value of nonzero means that the data is successfully validated.

In other words: TRUE -> from screen, FALSE -> to screen
Cool | :cool:

Other way:
set up text directly in the Edit similar:
m_myEdit.SetWindowText(youStringHere);

Hope this help.

Vitali

rohit.dhamija6-Aug-03 2:24

rohit.dhamija

6-Aug-03 2:24

Dear All,

I am developing an application using MFC VC++ Version 6.0 for Windows 2000 which shows the list of drives present in system. I am showing this list of drives with checkbox corresponding to it in a listbox.

I am using CCheckListBox class for this. When ever a user checks or unchecks a drive, an event should be generated showing which drive is selected. (eg. a messagebox should appear: C:\ is selected or C:\ is unselected )

Can any body tell me which event to capture. I tried using LBN_SELCHANGE but it didnot worked properly.

Rohit

Re: CheckListBox event for checkbox

David Crow6-Aug-03 2:48

David Crow

6-Aug-03 2:48

Use the CLBN_CHKCHANGE notification.

Re: CheckListBox event for checkbox

rohit.dhamija6-Aug-03 3:09

rohit.dhamija

6-Aug-03 3:09

Hi again,
I captured LBN_SELCHANGE event and put following code in my application
///////////////////////////////////////////////////////
void CDataSpaceDlg::OnSelchangeLstdrv()
{
if(m_listdrive.GetCheck(0))
AfxMessageBox("hi I am checked");
if(m_listdrive.GetCheck(0)==0)
AfxMessageBox("hi I am not checked");
}
//////
where m_listdrive is a variable of type CCheckListBox.
m_listdrive.GetCheck(0) gets the check type of the 0 index (c:\ corresponding to it)

It works fine when we click on this checklistbox but i have another checklistbox in that dialog .When i click on that checklistbox, then it throws a Debug Assertion failure Winctrl1.cpp line: 105
//////////////////////
Can anybody suggest a way out
rohit

Re: CheckListBox event for checkbox

David Crow6-Aug-03 3:15

David Crow

6-Aug-03 3:15

Have you looked at line 105 of Winctrl1.cpp? Notice the hard-coded assertion? It's telling you that your derived class has to implement DrawItem(), as well as the other two.

Inserting extended character

JensB6-Aug-03 2:06

JensB

6-Aug-03 2:06

Hi
I have a deutsch word 'äuBerst'.
I can't type that 'B' correctly in here neither.

How can i assign that word to a CString.
CString strMyWord = "äuBerst";

The 'B' needs to be changed to the deutsch version.

Anyone have any idea how to insert this extended character to the text?

Greetings
Jens

static system wide singleton

Dangleberry6-Aug-03 1:58

Dangleberry

6-Aug-03 1:58

Hi all, I have searched the web all over, and codeproject.com for an answer to this problem, and am empty handed. I have an app that loads a dll. I have a file management class (for loading files and managing their HANDLES etc.) In the app I use the notation io::Open(blah) to open the files using a static function which physically loads the file and keeps track of it in a list. However, when I try to load a file from the dll, the static io class is mapped to another area of memory and its list is NULL. How can I make it so that the io class is a system wide static class so that any instance within the current process can access the same static data? Any links or advice is very welcome Smile | :)

jhwurmbach6-Aug-03 2:19

jhwurmbach

6-Aug-03 2:19

You could make Open(blah) a function of your application class.
Then your DLL would get a pointer to that application object and you could call Open(blah) via that pointer. The list would then sit in the application and the dll would not need to know about foreign memory.

Who is 'General Failure'? And why is he reading my harddisk?!?

Ryan Binns6-Aug-03 2:25

Ryan Binns

6-Aug-03 2:25

Dangleberry wrote:
How can I make it so that the io class is a system wide static class so that any instance within the current process can access the same static data?

You can only do that by making its members non-static, and creating an instance of it in your application, then passing that instance to your DLL so that you application and DLL use the same instance of the class.

The fact that the members are static is only important at compile time. The DLL and application are compiled separately, and so they both get copies of the static data.

Hope this helps,

Ryan

"Punctuality is only a virtue for those who aren't smart enough to think of good excuses for being late" John Nichol "Point Of Impact"

Dangleberry7-Aug-03 3:03

Dangleberry

7-Aug-03 3:03

Yeah this is the way I was going to do it, but if I have multiple dll's for say different aspects of the app I'm going to have to distribute the pointer everywhere. I have managed to find an article on data_seg which allows static variables to share a common place in memory, but I have not yet managed to get it to work. I'd like it so that if I call io::Open() in my app or in any dll the same instance of io (and its static data members) are used in the function (can I actually pass an instance of a static class through and assign it to the dll instance?). I know I could pass a pointer through and use io->Open but I prefer the static function approach. Thanks for all responses, much appreciated.

Ryan Binns7-Aug-03 3:10

Ryan Binns

7-Aug-03 3:10

Dangleberry wrote:
if I have multiple dll's for say different aspects of the app I'm going to have to distribute the pointer everywhere.

Unfortunately, thats the price to pay for wanting a centralised way of working with things.

Dangleberry wrote:
I have managed to find an article on data_seg which allows static variables to share a common place in memory, but I have not yet managed to get it to work.

Creating a shared data segment? I think that only works for multiple instances of the same DLL.

Basically, I think you'll find that the only way you can do it is by passing a pointer to an instance of the class to all your DLLs.

Ryan

"Punctuality is only a virtue for those who aren't smart enough to think of good excuses for being late" John Nichol "Point Of Impact"

Vitali Halershtein6-Aug-03 3:05

Vitali Halershtein

6-Aug-03 3:05

Hi,

If you use MFC compatible dll don't forget to call:

AFX_MANAGE_STATE(AfxGetStaticModuleState());

Vitali

Directory selection

BoudewijnEctor6-Aug-03 1:58

6-Aug-03 1:58

Hi,

I've (finally) succeeded in generating a dialog box for selecting directories, but I'm getting an error:

First-chance exception at 0x70bf6827 in F2F.exe: 0xC0000005: Access violation writing location 0x0063b058.
Unhandled exception at 0x70bf6827 in F2F.exe: 0xC0000005: Access violation writing location 0x0063b058.
The thread 'Win32 Thread' (0x54c) has exited with code 128 (0x80).
The thread 'Win32 Thread' (0x57c) has exited with code 128 (0x80).
The program '[784] F2F.exe: Native' has exited with code 128 (0x80).

This is my code, can you tell me what's wrong:

void IO_scherm_multiinput::OnBnClickedButton1()<br />
{<br />
	<br />
			<br />
	BROWSEINFO* b=new BROWSEINFO();<br />
	LPTSTR buf="Undef BE";<br />
	<br />
	int image=-1;<br />
	b->hwndOwner=this->m_hWnd;<br />
	b->iImage=image;<br />
	<br />
	b->lpszTitle="Please select a driectory for IO";<br />
	b->pidlRoot=NULL;<br />
	b->pszDisplayName=buf;<br />
	<br />
	b->ulFlags=BIF_BROWSEINCLUDEFILES;<br />
	LPITEMIDLIST x=SHBrowseForFolder(b);<br />
		<br />
}

Re: Directory selection

Ryan Binns6-Aug-03 2:12

Ryan Binns

6-Aug-03 2:12

Your display name buffer is probably being overrun. The SHBrowseForFolder() function assumes that pszDisplayName is MAX_PATH characters long, whereas in your code it is only 9 characters long. Do it like this:

void IO_scherm_multiinput::OnBnClickedButton1()
{
    BROWSEINFO* b=new BROWSEINFO();
    LPTSTR buf=new TCHAR[MAX_PATH];
    _tcscpy(buf, "Undef BE");
 
    int image=-1;
    b->hwndOwner=this->m_hWnd;
    b->iImage=image;
 
    b->lpszTitle="Please select a driectory for IO";
    b->pidlRoot=NULL;
    b->pszDisplayName=buf;
 
    b->ulFlags=BIF_BROWSEINCLUDEFILES;
    LPITEMIDLIST x=SHBrowseForFolder(b);
    delete [] buf;  // Delete the memory when you're finished with it
}

Hope this helps,

Ryan

"Punctuality is only a virtue for those who aren't smart enough to think of good excuses for being late" John Nichol "Point Of Impact"

Re: Directory selection

BoudewijnEctor6-Aug-03 3:10